Inertia safety device for a door latch



Dec. 16, 1958 J. D. LESLIE INERTIA SAFETY DEVICE FOR A DOOR LATCH 2Sheets-Sheet 1 INVENTOR. BY c/Z/Wfifl 06256? fi (51/ I Filed Apri}. 26,1956 A 7' TOP/V5 Y Dec. 16, 1958 J. D. LESLIE INEIRTIA SAFETY DEVICE FORA DOOR LATCH Filed April 26, 1956 2 Sheets-Sheet 2 V? IN VIENTOR.

ATTO/PNEY 2,864,641 lNERTIA SAFETY DEVICE FGR A noon LATCH James D.Leslie, Birmingham, Mich, assignor to General Motors Corporation,Detroit, Mich., a corporation of Delaware Application April 26, 1956,Serial No. 580,949

7 Claims. (Cl. 292-3363) This invention relates to an inertia safetydevice for a door latch, and more particularly to an inertia safetydevice in combination with an automobile door latch actuator.

One feature of the invention is that it provides an improved inertialock device; another feature of the invention is that it provides animproved door latch actuator; a further feature of the invention is thatit prevents door rebound; yet a further feature of the invention is thatit provides means for blocking a push button door latch operator fromoperation in the event the push button is initially moved at anabnormally rapid speed; still another feature of the invention is thatit provides improved actuating apparatus for a door latch including ahandle device having a stop portion, a latch actuating device mounted onthe handle member and including a push button and an actuating rod, andan inertia lock member mounted on one of said devices and engageablewith the other of said devices in response to rapid movement of the pushbutton for preventing additional movement of said push button to unlatchthe door.

Other features and advantages of the invention will be apparent from thefollowing description and from the drawings, in which:

Fig. l is a fragmentary side elevational view of an a tomobile havingactuating apparatus for the door latch according to this invention;

Fig. 2 is an enlarged horizontal fragmentary section taken along theline 22 of Fig. 1;

Fig. 3 is a sectional view similar to Fig. 2 but showing the parts in adifferent position;

Fig. 4 is a vertical section taken along the line 4-4 of Fig. 2;

Fig. 5 is an enlarged fragmentary elevation of a modified form of theinvention; and Fig. 6 is a vertical section taken along the line 6-6 ofFig. 5.

In automobiles in which the door latch outside actuator comprises a pushbutton mounted in a stationary handle it often happens that when thedoor is slammed shut inertia forces acting upon the push button and theactuating rod which it controls cause a rapid movement of the pushbutton relative to the then stationary door when the door reaches itsclosed position so that the push button assembly momentarily trips thedoor latch, permitting the door to rebound at least to its safety latchposition. This invention provides a novel inertia lock device associatedwith the push button assembly for preventing movement of the push buttonin the event of and in response to rapid initial movement thereof. Theinertia lock device does not, however, prevent normal relatively slowoperation of the push button to open the door. In the event theautomobile should roll over on its side so that the push button strikesthe ground, the inertia lock will prevent movement of the push button totrip the door latch, thus providing an important safety feature.

In the drawings, an automobile 14 has a front door 12 and a rear door14. While both doors may have similar latching devices, only the frontdoor latch 16 is illus- 2,864,641 atented Dec. 16, 1958 I in tratedfragmentarily in Fig. 1. The front door has an outer handle 18 mountinga slidable push button assembly 20 including a push rod 22 for operatingthe door latch 16. Similarly, the rear door has a handle 24 mount ing apush button assembly 26 for operation of the rear door latch, which isnot illustrated.

Figs. 2, 3 and 4 show the front door handle and the latch actuatingmeans in detail. The apparatus may be similar for the rear door. As isconventional with push button door latch operators, the handle 18 isfixedly mounted on the door and has a gripping portion 23 for swingingthe door open and closedand a body portion 39 with a bore 31 includingan enlarged chamber 32 in which the push button 20 slides. The actuatingpush rod 22 projects from the push button through the bore 31 of thedoor handle into the interior of the door and terminates in a button 38which, when the push button is depressed as shown in Fig. 3, engages andswings a bell crank 40 pivotally mounted-on a stud 42 and support 43inside the door. Swinging the bell crank 40 lifts up on rod 23 to tripthe latch 16. Details of a suitable latch and tripping arrangement ofthis type are shown in the copending application of Robert M. Hebertentitled, Rotary Bolt Door Latch, filed January 19, 1955 as S. N.482,705 and assigned to the assignee of this application.

The push-button assembly is urged toward the normal extended operatingposition of Figs. 2 and 4 by a spring 44in the chamber 32. Because itisdesired not to make the push button difficult to operate, the forceexerted by spring 44 is quite light. A stop to hold the push buttonassembly in the chamber 32 is provided by a screw 46 which is engaged bya shoulder 43 on the actuating rod when the parts are in the position ofFig. 2.

The push button assembly, including the push button 20, the actuatingrod 22 and the button 38, embodies substantial mass. When the door isslammed shut, the inertia of this mass may cause the push-buttonassembly to move relative to the door from the normal operating positionof Fig. 2 to the operated position of Fig. 3 to trip the latch 16momentarily at the instant the door reaches its closed position. Whenthis happens, the door may rebound fully open, or at least to its safetylatched position. This rebound action is aided by a resilient sealingweather strip around the periphery of the door, the weather strip beingdeflected or compressed when the door is closed.

This invention provides a novel inertia device associated with the latchto prevent the push button from moving relative to the door when thedoor is closed or whenever the push button 20 starts to move withabnormal speed. The inertia device is so arranged that it has no eflfectupon relatively slow normal finger operating movement of thepush-button.

An inertia member 50 is swingably mounted on the actuating rod 22 on apin 52, the inertia member lying in a slot 53 formed in the actuatingrod. The pin 52 also mounts a coil spring 54, one end 55 of which bearsagainst the inertia member 50 to urge it to swing in a clockwisedirection from the position of Fig. 2 to the position of Fig. 3. Theinertia member has an intermediate portion of its left edge (as theparts appear in Figs. 2 and 3) formed as a cam surface 56 which normallyprojects out of the slot 53 as shown in Fig. 2. The cam surfaceterminates at its inner end in a stop shoulder 57, and a complementarystop shoulder 58 is formed in the bore 31 of the body portion of thehandle. When the push button assembly is in its normal extended positionas shown in Pig. 2, the stop shoulder 57 on the inertia member is spacedoutwardly away from the complementary stop shoulder 58 on the handle,but if the push button moves inwardly and the inertia member does notswing downwardly out of the way, these shoulders will abut to blockfurther inward movement of the push button. When the push button is inits normal extended position, a foot 60 on the end of the inertia member50 rests against the circumferential edge of the bore 31 to hold theinertia member in a position extending in alignment with the push buttonwith the handle stop shoulder 58 in the straight line path of movementof the inertia member stop shoulder 57 as shown in Fig. 2. In the eventof rapid initial movement of the push button, the shoulder 57 on theinertia member will move into blocking engagement with the shoulder 58on the door handle before the spring 54 swings the inertia member to aposition where the shoulder 57 moves out of the way of the shoulder 58.Therefore, upon rapid initial movement of the push button, the shoulders57 and 58 will abut and prevent further inward movement of the pushbutton assembly. However, if the push button is operated rela tivelyslowly as happens in normal opening of the door, the inertia member 50swings toward the position of Fig. 3 when the foot 60 leaves theperipheral rim of the bore 31. The end face 64 of the handle body 30 isdished as shown in Figs. 2, 3 and 4 to provide clearance for the endfoot 60 of the inertia member during the first part of this swingingmovement. When finger pressure on the push button is released, it isreturned by the spring 44 to the position of Fig. 2, the peripheral rimof the bore 31 camming the inertia member 50 back into alignment withthe push button assembly against the force of the spring 54 as soon asthe cam surface 56 and stop shoulder 57 pass the stop shoulder 58.

In addition to preventing door rebound when the door is slammed, thisdevice will also prevent the door from opening in the event theautomobile rolls over, since sudden inward movement of the push buttonwhen it strikes the ground would move the push button assembly rapidlyinwardly to bring the shoulders 57 and 58 into abutment before thespring 54 could swing the inertia member out of the way.

Figs. 5 and 6 show a modified form of the invention in which the inertiamember is gravity biased. In Figs. 5 and 6, the parts are designated bythe same reference characters as in Figs. 2, 3 and 4 with the additionof a prime Referring particularly to Fig. 6, the inertia member 50' isswingably mounted on the actuating rod 22' on a pin 52' which lies in ahorizontal plane so that the inertia member 50 is gravity biased toswing downwardly from the position of Fig. 6. When the parts are in theposition of Fig. 6, the dished end face 64' of the handle body 30' holdsthe inertia member 5419' up. When the push button is depressed in thenormal course of operation, the assembly, including the push rod 22',moves inwardly so that the foot 6i) of the inertia member 50' moves awayfrom the dished end face 64' of the handle, permitting the inertiamember 50 to swing downwardly under the influence of gravity. Theoperation is the same as that described above in connection with claims2, 3 and 4. If the push button is depressed relatively slowly as innormal operation, the inertia member will swing down before theshoulders 57, 58' abut. However, in the event of rapid initial movementof the push button, the shoulder 57 will move into blocking engagementwith the shoulder 58' before the force of gravity can swing the inertiamember downwardly to a position where the shoulder 57' moves out of theway of the shoulder 58'.

While I have shown and described one embodiment of my invention, it iscapable of many modifications. Changes, therefore, in the constructionand arrangement may be made without departing from the spirit and scopeof the invention as set forward in the appended claims.

I claim:

1. Actuating apparatus for a door latch, comprising: support meansincluding a body chamber portion; latch actuating means slidably mountedin the chamber of said body portion; and an inertia device swingablymounted on one of said means and engageable with the other of said meansin response to rapid initial movement of said latch actuating means forpreventing continued movement of said latch actuating means.

2. Actuating apparatus for a door latch, including: a handle memberhaving a body portion; latch actuating means movably mounted in the bodyportion of said handle member; and an inertia device swingably mountedon said latch actuating means and engageable with the body portion ofsaid handle member in response to rapid initial movement of said latchactuating means for preventing continued movement of said latchactuating means.

3. Actuating apparatus for a door latch, including: a handle memberhaving a body portion; latch actuating means comprising a push buttonand an actuating rod slidably mounted in the body portion of said handlemember; an inertia device swingably mounted on said actuating rod andengageable with the body portion of said handle member in response torapid initial movement of said latch actuating means for preventingcontinued movement of said latch actuating means.

4. Actuating apparatus for a door latch, including: a handle memberhaving a body portion with a stop shoulder thereon; latch actuatingmeans comprising a push button and actuating rod slidably mounted in thebody portion of said handle member; and an inertia device swingablymounted on said latch actuating means and engageable with said stopshoulder in response to rapid initial movement of said latch actuatingmeans for blocking continued movement of said actuating means, saidinertia device being out of engagement with said stop shoulder when thelatch actuating means is stationary in its normal position.

5. Actuating apparatus for a door latch, including: a handle memberhaving a body portion with a stop shoulder thereon; latch actuatingmeans comprising a push button and actuating rod slidably mounted in thebody portion of said handle member; an inertia device swingably mountedon said latch actuating means and engageable with said stop shoulder inresponse to rapid initial movement of said latch actuating means forblocking continued movement of said actuating means; means urging saidinertia device to swing away from said stop shoulder; and means swingingsaid inertia device into position to engage said stop shoulder when thelatch actuating means is in its normal position.

6. Actuating apparatus for a door latch, including: a handle memberhaving a chambered portion with a first stop shoulder therein; latchactuating means comprising a push button and actuating rod slidablymounted in the chamber of said body portion; spring means urging saidlatch actuating means to a normal extended position; an inertia deviceswingably mounted on said latch actuating means and having a second stopshoulder engageable with said first stop shoulder in response to rapidinitial movement of said latch actuating means for blocking continuedmovement of said latch actuating means; a spring urging said inertiadevice to swing away from said first stop shoulder; and complementarycam portions on said handle and said, inertia device for swinging saidinertia device into a position to engage said stop shoulder when thelatch actuating means is in its normal position wherein said first stopshoulder lies in the straight line path of movement of said second stopshoulder.

7. Actuating apparatus for a door latch, including: a handle memberhaving a body portion with a stop shoulder thereon; latch actuatingmeans comprising a push button and actuating rod slidably mounted in thebody portion of said handle member; an inertia device swingably mountedon said latch actuating means and engageable with said stop shoulder inresponse to rapid initial movement of said latch actuating means forblocking continued movement of said actuating means, said inertia 5device being so mounted on the latch actuating means that it is gravitybiased in a direction to swing away from said stop shoulder; and meansholding said inertia device into position to engage said stop shoulderwhen the latch actuating means is its normal position.

References Cited in the file of this patent UNITED STATES PATENTS

